Standardized endpoint definitions for trials of transcatheter left atrial appendage closure: a consensus from the Left Atrial Appendage Academic Research Consortium
Abstract Since its introduction in 2002, left atrial appendage closure (LAAC) has rapidly expanded as an alternative to anticoagulation in patients with atrial fibrillation at high risk of stroke. Harmonized processes for data collection, analysis, and reporting in LAAC trials are essential to enhance research quality and improve clinical practice. The Left Atrial Appendage Academic Research Consortium (LAARC) initiative is an independent collaboration of academic research organizations, cardiology and neurology experts, clinical trialists, and regulatory authorities from the USA, Europe, and Asia. The consortium engaged clinical experts, regulators—including the US Food and Drug Administration (FDA), European Notified Bodies, and Japan’s Pharmaceuticals and Medical Devices Agency (PMDA)—and industry leaders to define standardized study elements and endpoints for LAAC trials. Key considerations included alignment with prior Academic Research Consortium initiatives, procedural and mechanistic insights, and clinical relevance. Consensus definitions were proposed for mortality, stroke, bleeding, and device performance, along with composite endpoints for safety and effectiveness. The proposed LAARC consensus definitions aim to standardize endpoint reporting, improve comparability across studies, and support regulatory and clinical trial applications for this evolving therapy through broad dissemination in the peer-reviewed literature.
Long‐Term Outcomes Following Left Atrial Appendage Occlusion in Medicare Beneficiaries: Outcomes From the National Cardiovascular Data Registry
Background Percutaneous left atrial appendage occlusion (LAAO) is an alternative to long‐term anticoagulation for preventing ischemic stroke in patients with atrial fibrillation. There are limited long‐term outcomes data for “real‐world” patients undergoing LAAO. Methods We performed a retrospective cohort study using the National Cardiovascular Data Registry LAAO registry from January 1, 2016, through December 31, 2019. We linked LAAO data to inpatient Medicare fee‐for‐service claims data using probabilistic matching to establish a cohort of patients 65 years and older undergoing LAAO with a WATCHMAN device. The primary outcomes were any stroke and all‐cause mortality. Results A total of 34 975 patients with a mean±SD CHA 2 DS 2 ‐VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke or transient ischemic attack, vascular disease, age 65 to 74 years, and sex category) score of 4.7±1.4 were included. The median follow‐up was 2.8 years (interquartile range, 2.2–3.7 years). The cumulative incidence of any stroke was 1.57 per 100 person‐years (95% CI, 1.45–1.70), with a 1‐year and 5‐year any stroke estimate of 1.70% (95% CI, 1.57–1.84%) and 5.70% (95% CI, 5.37–6.05%), respectively. The cumulative incidence of ischemic stroke was 1.36 per 100 person‐years (95% CI, 1.25–1.48), with a 1‐year and 5‐year ischemic stroke estimate of 1.42% (95% CI, 1.30–1.54%) and 5.03% (95% CI, 4.71–5.36%), respectively. The cumulative incidence of death was 10.82 per 100 person‐years (95% CI, 10.49–11.13), with a 5‐year mortality estimate of 44.34% (95% CI, 43.35–45.23%). Conclusions Long‐term stroke rates in a large nationally representative cohort of Medicare patients following LAAO were low and durably consistent during long‐term follow‐up despite a high thromboembolic risk. High mortality rates in this elderly population underscore the importance of incorporating patient values and preferences when considering LAAO.
Abstract 6932: Safety of Left Atrial Appendage Closure on Uninterrupted Warfarin Therapy
Introduction: Left atrial appendage closure (LAAC) device for stroke prevention is a safe and effective alternative to oral anticoagulation (OAC) in patients with atrial fibrillation (AF). The safety of performing LAAC on uninterrupted warfarin (UW) compared to interrupted warfarin (IW) is currently unknown. Hypothesis: Complication rates of performing LAAC on UW vs. IW will be similar. Methods: We reviewed the data from the second half of PROTECT-AF trial, PREVAIL trial, CAP and CAP2 registries. Patients were categorized to the UW group if INR on the day of the procedure was ≥2 and to the IW group if INR was <2. Procedural complications within 7 days of LAAC were reviewed. An association between complications and AC strategy was analyzed. Results: Data from 1580 patients were reviewed and 294 patients (18.6%) received LAAC on UW. The UW group had a mean INR of 2.4±0.4 and IW group had a mean INR of 1.3±0.3. There were several differences in baseline characteristics: lower BMI in the UW group (28.6±5.3 vs 29.5±6.0, p=0.01), fewer patients with hypertension in the UW group (87.1% vs 91.1%, p=0.04), lower HAS-BLED score in the UW group (2.0±1.0 vs 2.1±1.0, p<0.01), and more patients with persistent AF in the UW group (37.1% vs 26.4%, p<0.01). Overall, there were no significant differences in total or individual complication rates between the two groups (UW 5.1% vs IW 6.1%, p=0.59). Although not statistically significant, lower event rates were noted in the UW group for the following: stroke (0% vs 0.3%, p>0.99), pericardial effusion requiring intervention (1.7% vs 1.8%, p>0.99), pseudoaneurysm (0% vs 0.4%, p=0.59), hematoma (0% vs 0.2%, p>0.99), and device embolism (0% vs 0.2%, p=1.0). The UW group had statistically insignificant higher events rates of AV fistula (0.3% vs 0%, p=0.19) and major bleeding requiring transfusion (1% vs 0.5%, p=0.38). In addition, there was no significant difference in periprocedural ischemic stroke (0% vs 0.3%, p>0.99). Conclusion: In this retrospective analysis, no significant difference was observed in procedural complication rates when performing LAAC on UW vs. IW. These results suggest that LAAC can be safely performed without interruption of OAC.
Two‐Year Outcomes With a Next‐Generation Left Atrial Appendage Device: Final Results of the PINNACLE FLX Trial
Background The PINNACLE FLX (Protection Against Embolism for Non‐valvular AF [Atrial Fibrillation] Patients: Investigational Device Evaluation of the Watchman FLX LAA [Left Atrial Appendage] Closure Technology) trial evaluated the safety and efficacy of a next‐generation left atrial appendage closure device (WATCHMAN FLX; Boston Scientific, Marlborough, MA). At 1 year, the study met the primary end points of safety and anatomical efficacy/appendage closure. This final report of the PINNACLE FLX trial includes the prespecified secondary end point of ischemic stroke or systemic embolism at 2 years, also making it the first report of 2‐year outcomes with this next‐generation left atrial appendage closure device. Methods and Results Patients with nonvalvular atrial fibrillation with CHA 2 DS 2 ‐VASc score ≥2 (men) or ≥3 (women), with an appropriate rationale for left atrial appendage closure, were enrolled to receive the left atrial appendage closure device at 29 US centers. Adverse events were assessed by an independent clinical events committee, and imaging was assessed by independent core laboratories. Among 395 implanted patients (36% women; mean age, 74 years; CHA 2 DS 2 ‐VASc, 4.2±1.5), the secondary efficacy end point of 2‐year ischemic stroke or systemic embolism was met, with an absolute rate of 3.4% (annualized rate, 1.7%) and an upper 1‐sided 95% confidence bound of 5.3%, which was superior to the 8.7% performance goal. Two‐year rates of adverse events were as follows: 9.3% all‐cause mortality, 5.5% cardiovascular death, 3.4% all stroke, and 10.1% major bleeding (Bleeding Academic Research Consortium 3 or 5). There were no additional systemic embolisms, device embolizations, pericardial effusions, or symptomatic device‐related thrombi after 1 year. Conclusions The secondary end point of 2‐year stroke or systemic embolism was met at 3.4%. In these final results of the PINNACLE FLX trial, the next‐generation WATCHMAN FLX device demonstrated favorable safety and efficacy outcomes.
Indications for Left Atrial Appendage Occlusion in the United States and Associated In-Hospital Outcomes: Results From the NCDR LAAO Registry
Background: The Food and Drug Administration approved left atrial appendage occlusion with the Watchman device for patients who are at increased stroke risk and are suitable for oral anticoagulation but who have an appropriate reason to seek a nondrug alternative. These broad criteria raise the question of their interpretation in clinical practice. There is a lack of studies comprehensively evaluating the indications for Watchman implantation among a large series of patients from contemporary, real-world practice in the United States. Methods: We used the National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry to identify Watchman procedures performed between 2016 and 2018. We assessed procedural indications for Watchman implantation in the United States and evaluated the association between procedural indications and in-hospital adverse events. Results: A total of 38 314 procedures were included. The mean patient age was 76.1±8.1 years, and 58.9% were men. The mean CHA 2 DS 2 -VASc score was 4.8±1.5, whereas the mean hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol (HAS-BLED) score was 3.0±1.1. Prior stroke or transient ischemic attack was reported in 40.2% and prior bleeding in 70.1%, with gastrointestinal bleeding being most common (41.9%). The most common site-reported procedural indications for Watchman implantation were increased thromboembolic risk (64.8%) and history of major bleed (64.3%), followed by high fall risk (35.5%). Most (71.9%) had ≥2 procedural indications. Patients with high fall risk had increased risk of in-hospital adverse events (adjusted OR, 1.12; P =0.025), but no other differences were found in the risk of in-hospital adverse events by procedural indication. Conclusions: Among patients in the National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry, the most common procedural indications for Watchman implantation were increased thromboembolic risk, history of major bleed, and high fall risk. A majority of patients had multiple procedural indications. High fall risk conferred a modestly increased risk of in-hospital adverse events.
Antithrombotic Therapy in Patients With Atrial Fibrillation Treated With Oral Anticoagulation Undergoing Percutaneous Coronary Intervention
A growing number of patients undergoing percutaneous coronary intervention (PCI) with stent implantation also have atrial fibrillation. This poses challenges for their optimal antithrombotic management because patients with atrial fibrillation undergoing PCI require oral anticoagulation for the prevention of cardiac thromboembolism and dual antiplatelet therapy for the prevention of coronary thrombotic complications. The combination of oral anticoagulation and dual antiplatelet therapy substantially increases the risk of bleeding. Over the last decade, a series of North American Consensus Statements on the Management of Antithrombotic Therapy in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention have been reported. Since the last update in 2018, several pivotal clinical trials in the field have been published. This document provides a focused updated of the 2018 recommendations. The group recommends that in patients with atrial fibrillation undergoing PCI, a non–vitamin K antagonist oral anticoagulant is the oral anticoagulation of choice. Dual antiplatelet therapy with aspirin and a P2Y 12 inhibitor should be given to all patients during the peri-PCI period (during inpatient stay, until time of discharge, up to 1 week after PCI, at the discretion of the treating physician), after which the default strategy is to stop aspirin and continue treatment with a P2Y 12 inhibitor, preferably clopidogrel, in combination with a non–vitamin K antagonist oral anticoagulant (ie, double therapy). In patients at increased thrombotic risk who have an acceptable risk of bleeding, it is reasonable to continue aspirin (ie, triple therapy) for up to 1 month. Double therapy should be given for 6 to 12 months with the actual duration depending on the ischemic and bleeding risk profile of the patient, after which patients should discontinue antiplatelet therapy and receive oral anticoagulation alone.
Antithrombotic Therapy in Patients With Atrial Fibrillation Treated With Oral Anticoagulation Undergoing Percutaneous Coronary Intervention
The optimal antithrombotic treatment regimen for patients with atrial fibrillation undergoing percutaneous coronary intervention with stent implantation represents a challenge in clinical practice. In 2016, an updated opinion of selected experts from the United States and Canada on the treatment of patients with atrial fibrillation undergoing percutaneous coronary intervention was reported. After the 2016 North American consensus statement on the management of antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention, results of pivotal clinical trials assessing the type of oral anticoagulant agent and the duration of antiplatelet treatment have been published. On the basis of these results, this focused update on the antithrombotic management of patients with atrial fibrillation undergoing percutaneous coronary intervention recommends that a non–vitamin K antagonist oral anticoagulant be preferred over a vitamin K antagonist as the oral anticoagulant of choice. Moreover, a double-therapy regimen (oral anticoagulant plus single antiplatelet therapy with a P2Y 12 inhibitor) by the time of hospital discharge should be considered for most patients, whereas extending the use of aspirin beyond hospital discharge (ie, triple therapy) should be considered only for selected patients at high ischemic/thrombotic and low bleeding risks and for a limited period of time. The present document provides a focused updated on the rationale for the new expert consensus–derived recommendations on the antithrombotic management of patients with atrial fibrillation treated with oral anticoagulation undergoing percutaneous coronary intervention.